If a wild animal gets fleas, why don’t they keep multiplying until the animal is totally engulfed ? I would guess that it has happened but every wild animal with fleas isn’t doomed to this. Right? Is the population of fleas that can live on a single animal self limiting somehow?
Fleas don’t actually live on the animal – they just jump aboard to feed. You’ll occasionally find flea larvae on the animal, but they don’t bite.
What governs it is that the entire flea population doesn’t live on the fox 24/7, living and breeding over and over again right there, the way a population of guppies lives in their fish tank. The female flea lays eggs, the eggs drop off onto the grass, they hatch out into larvae, which then grow into fleas waiting to hop on a passing fox, and while they’re roaming around in the grass as larvae and adult fleas waiting for another fox to walk by, they’re subject to parasites like nematodes, and predators like ants and spiders. So it’s while they’re roaming around in the grass that their numbers are controlled. The few that make it onto the fox are the survivors.
Thanks! Makes sense, I was assuming that once they found a host, they stayed on there.
As a quick aside, it is not unusual to see moderate anemia due to fleas in house pets. I have seen neonates die due to exsanquination from severe infestation.